Adjustable sidetone and active noise cancellation in headphones and similar devices

ABSTRACT

A headphone device comprising active noise cancellation means (ANC) having a feedback (FB) signal path, a feed forward (FF) signal path and a sidetone signal path, where the headphone is provided with a control member (1, 11) that can be displaced or rotated between opposite positions, where the control member (1, 11) is configured such that the gain of the FF signal path and the gain of the sidetone signal path are controllable by the control member (1, 11) in such manner that when the control member (1, 11) is at one extreme position, the gain of the FF signal path is maximum and the gain of the sidetone signal path is minimum and when the control member (1,11) is at the opposite extreme position, the gain of the FF signal path is minimum and the gain of the sidetone signal path is maximum.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to Danish Application Number PA 202001373, filed on Dec. 7, 2020, which is incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present invention relates generally to the field of headphones,headsets or earphones and more specifically to headphones, headsets orearphones provided with active noise cancelling (ANC).

BACKGROUND OF THE INVENTION

Many headphones, headsets and earphones are equipped with one or moremicrophones. These microphones are positioned in such a way that theycan be used as voice microphone(s) during voice calls and/or asmicrophones for active noise cancellation (ANC).

When the user is wearing a headphone, headset or earphone the ear willtypically be blocked physically by the device. This physical blockingwill make it difficult for the user to hear his or her own voice clearlyand with a natural timbre or sound quality during a voice call.

To compensate for this blocking, an amount of the sound of the user'sown voice is transferred via the voice microphone(s) as an electricalsignal to the loudspeaker(s) in the user's headphone, headset orearphone. This electrical signal is normally called sidetone.

Adding sidetone can create negative side effects when a headphone,headset or earphone is used in noisy or windy environments, asenvironmental noise or wind noise can be transferred to theloudspeaker(s) in the headphone, headset or earphone via the sidetonepath.

Microphones used for voice pickup are often placed on the outside of theheadphone, headset or earphone and can easily be exposed to wind,leading to undesired wind noise or distortion, which is clearly audiblefor the user via the sidetone path.

Active Noise Cancelling (ANC) headphones, headsets or earphones oftenuse microphones placed on the outside of the headphone, headset orearphone as well as microphones placed on the inside of the headphone,headset or earphone.

Microphones on the outside of the headphone, headset or earphone willpick up ambient noise outside the headphone, headset or earphone to beused for the feed-forward part of the ANC system.

Microphones placed on the inside of the headphone, headset or earphonewill pick up ambient noise inside the headphone, headset or earphone tobe used for the feedback part of the ANC system.

The microphones on the outside of the headphone, headset or earphone aremuch more exposed to wind compared to microphones on the inside of theheadphone, headset or earphone, which microphones are protected fromexposure to the wind.

OBJECTS OF THE INVENTION

As the optimal balance between the feedback signal, the feed forwardsignal and the sidetone signal depends on the acoustical environment inwhich the headphone, headset or earphone is used as well as on userpreferences, it is an object of the present invention to provide aheadphone, headset or earphone comprising an active noise cancelling(ANC) system and a sidetone functionality that makes it possible for theuser to obtain the above mentioned optimal balance no matter where andin which situations the headphone, headset or earphone is being used.

It is a further object of the present invention to provide a headphone,headset or earphone that is configured such that the optimal balancebetween the feedback signal, the feed forward signal and the sidetonesignal can be adjusted by the user during use of the headphone, headsetor earphone in a simple user-friendly manner.

DISCLOSURE OF THE INVENTION

Throughout the following description as well as in the claims the terms“headphone” or “headphone device” comprise both a headphone, a headsetand an earphone as well as any similar head-worn or ear-worn deviceconfigured to pick up sound both in the outer ear of the user, when theuser is wearing the device and in the environment immediately outside ofthe device.

The above and further objects and advantages are obtained by theprovision of a headphone according to the invention.

During voice calls this invention makes it possible for the user toadjust the level of the sidetone and feed-forward ANC on the productitself to obtain the preferred balance according to the environment theheadset is used in, such as quiet, noisy, or windy conditions.

In relatively quiet environments the user will typically prefer amaximum level or gain of the sidetone to be able to hear his or her ownvoice clearly and naturally.

In windy environments the user will typically prefer a setting where thelevel or gain of the sidetone and of the feed-forward part of the ANCsystem are both set to minimum—to minimize the transmission of windnoise to the loudspeaker(s) in the headset.

In very noisy environments the user will typically prefer a settingwhere the level or gain of the sidetone is set to minimum and the levelor gain of the feed-forward ANC is set to maximum—to maximize noisecancellation.

At all settings, the level or gain of the feedback part of the ANCsystem will according to the present invention typically be at maximumto reduce the occlusion effect, i.e. to reduce the boomy sound of theuser's own voice inside the head when the ears are blocked, butaccording to specific embodiments of the invention, also the level orgain of the feedback path can be varied.

According to the invention, the level or gain of the sidetone and/or thefeed forward path can be varied smoothly (or in steps) with only asingle control element (e.g. a rotating wheel/knob or a slider) on theproduct making it very easy for the user to obtain the optimumcombination of the relative level or gain of the sidetone, the feedforward path and the feedback path according to precisely the acousticenvironment in which the user is presently situated as well as to his orher specific preferences.

According to the invention, the above-mentioned and further objects andadvantages are provided by a headphone device comprising active noisecancelling means (ANC) having a feedback (FB) signal path, a feedforward (FF) signal path and a sidetone signal path, where the headphoneis provided with a control member that can be displaced or rotatedbetween opposite positions, where the control member is configured suchthat the gain of the FF path and the gain of the sidetone path arecontrollable by the control member in such manner that when the controlmember is at one extreme position, the gain of the FF path is maximumand the gain of the sidetone path is minimum and when the control memberis at the opposite extreme position, the gain of the FF path is minimumand the gain of the sidetone path is maximum.

In an embodiment of the invention, the gain of the feedback signal pathFB is fixed at a predetermined value.

In an embodiment of the invention, the gain of the feedback signal pathis variable.

In an embodiment of the invention, the control member is a rotary knobor similar member.

In an embodiment of the invention, the control member is a slidercontrol, such as a touch bar.

In an embodiment of the invention, the control member is a + and −button which moves the the setting up and down a table of settings (asexemplified in the detailed description of the invention). The + and −button could be implemented as physical buttons or touch buttons.

In an embodiment of the invention, the sidetone and FF settings areoperated by a touch panel or by one or more buttons.

In an embodiment of the invention, the headphone device comprises onesingle button or one single touch area configured such that the user cancycle through a table containing the on/off state or intermediatesettings of the sidetone and FF signal paths thereby moving one row eachtime a button/area is pressed or touched.

In an embodiment of the invention, the headphone device comprises twobuttons or touch areas configured such that the user can cycle through atable containing the on/off state or intermediate settings of thesidetone and FF signal paths thereby moving one row up each time onebutton/area is pressed or touched and moving one row down each time theother button/area is pressed or touched.

In the above embodiments, an intermediate setting could be any sidetonegain between 0% and 100% and similarly, any FF signal path gain between0% and 100%.

In an embodiment of the invention, the control member is provided on theheadphone.

In an embodiment of the invention, the control member is provided on adevice that is in functional communication with the headphone.

BRIEF DESCRIPTION OF THE DRAWINGS

Further benefits and advantages of the present invention will becomeapparent after reading the detailed description of non-limitingexemplary embodiments of the invention in conjunction with theaccompanying drawings, wherein

FIG. 1 shows a plot schematically illustrating the effect of adjusting asingle user operable member on a headphone according to an embodiment ofthe invention;

FIG. 2 shows pre-set options that can be activated by for instance apress button or the like as an alternative to the continuous controlprovided by a rotatable knob or a slider bar; and

FIG. 3 shows an example of a gain table used in an embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

In the following a detailed description of an example embodiment of theinvention is given. It is however understood that the principles of theinvention could be embodied in other ways.

With reference to FIG. 1 there is shown a plot that schematicallyillustrates the effect of adjusting a single user operable member 1 (inthis example embodiment a rotatable knob) provided on a headphoneaccording to an embodiment of the invention. FIG. 1 shows the gain ofthe sidetone path and the gain of the feed forward path as a function ofthe rotation of the control knob 1. In the embodiment of the inventionshown in FIG. 1 , the gain of the feedback path is constant and equal to0 dB (its maximum value).

As schematically illustrated in FIG. 1 , when the control knob 1 isrotated from the middle position 4 counter-clockwise 2, the gain 5 ofthe side tone path increases from a very low level (−X dB) to the samelevel (0 dB) as the gain 7 of the feedback path. When the control knob 1is at any position from the middle position 4 and to the extremecounter-clockwise position, the gain 6 of the feed forward path remainsat the very low level (−X dB). Hence, when the control knob 1 is rotatedcounter-clockwise 2 from the middle position 4, the user of theheadphone is substantially only presented with the effect of thesidetone and the feedback path.

As indicated in FIG. 1 , a rotation of the control knob 1 to largecounter-clockwise positions (between about 40 and 100%counter-clockwise) in the figure would be the adjustment of the controlknob 1 that a user would typically choose during normal voice calls 8,i.e. during voice calls in substantially quiet surroundings without windnoise.

When the control knob 1 is rotated from the middle position 4 clockwise3, the gain 6 of the feed forward path increases from a very low level(−X dB) to the same level (0 dB) as the gain 7 of the feedback path.When the control knob 1 is at any position from the middle position 4and to the extreme clockwise position, the gain 6 of the sidetone pathremains at the very low level (−X dB). Hence, when the control knob 1 isrotated clockwise 3 from the middle position 4, the user of theheadphone is substantially only presented with the effect of the feedforward and the feedback path.

As indicated in FIG. 1 , a rotation of the control knob 1 to largeclockwise positions (between about 40 and 100% clockwise) in the figurewould be the adjustment of the control knob 1 that a user wouldtypically choose during voice calls in very noisy environments 10.

As indicated in FIG. 1 , a rotation of the control knob 1 to mid-wisepositions (between 40% counter-clockwise and 40% clockwise) in thefigure would be the adjustment of the control knob 1 that a user wouldtypically choose during outdoor voice calls 9.

In an embodiment of the invention, during a voice call, it is proposedto use the below settings (c.f. FIG. 1 ):

1) FB ANC is always active irrespective of control knob 1 rotation orslider position.

2) Turning the control knob 1 clockwise 3 from the middle position 4—ordisplacing a corresponding slider control member from its middleposition towards one side—will change the gain or level of FF ANC from−X dB to 0 dB (0 to 100% FF ANC).

3) Turning the control knob 1 counter-clockwise 2 from the middleposition 4—or displacing a corresponding slider control member from itsmiddle position towards the opposite side—will change the sidetone gainor level From −X dB to 0 dB (0 to 100% sidetone)

Alternatively, the sidetone and FF ANC could also be operated by a touchpanel or by one or more buttons as described below.

In case of a single button or one single touch area, the user would forinstance cycle through a table of settings, such as the one shown inFIG. 2 , moving one row for each button press/touch.

In case of two buttons, one button could be configured to move one rowup in the table and the other button could be configured to move one rowdown in the table.

During a voice call the user can select different presets for sidetoneand feed-forward ANC settings on the product itself (by toggling between3 or more presets, for instance 5 or more rows, to facilitate a fineradjustment resolution) to obtain the preferred setting according to theenvironment the headset is used in, such as quiet, noisy, or windyconditions.

Preset 1: In relatively quiet environments, the user will typicallyprefer to have maximum (100%) sidetone to be able to hear his or her ownvoice clearly and naturally.

Preset 2: In windy environments the user will typically prefer a settingwhere the sidetone and the feed-forward part of the ANC system are bothset to minimum (0%)—to minimize wind noise.

Preset 3: In very noisy environments the user will typically prefer asetting where the sidetone is set to minimum (0%) and the feed-forwardANC is set to maximum (100%)—to maximize noise cancellation.

In all presets, the feedback part of the ANC system will typical be atmaximum (100%) to reduce the occlusion effect, i.e. to reduce the boomysound of own voice inside the head when the ears are blocked.

With reference to FIG. 2 there is shown a table of preset options thatcan be activated by for instance a press button or the like as analternative to the continuous or stepwise control provided by arotatable knob or a slider bar corresponding to Preset 1 through 3mentioned above.

With reference to FIG. 3 there is shown an example of a gain table usedin an embodiment of the invention. It is however understood that othernumerical values than those given in the table can be used and that suchvalues would also fall within the scope of the invention.

The table comprises six columns I, II . . . VI. Column I show the effectof the feedback ANC expressed in percent and column II similarly showsthe effect of the feed forward ANC in percent. Column III shows theamount of sidetone also expressed in percent. Columns IV, V and VI showthe respective gains of the feedback (FB) signal path, the feed forward(FF) signal path and the sidetone signal path expressed in dB.

FIG. 3 further illustrates that the choice of ANC and Sidetonesettings—and hence the choice of the respective gains—can be obtained bythe user by means of a single control member, in the figure by means ofa slide bar 11 (for instance a touch bar) that, when displaced asindicated by arrow S from one extreme position providing maximum ANCeffect and no sidetone effect to the other extreme position giving nofeed-forward ANC effect and maximum sidetone effect, determines thebalance between the FB, FF and sidetone contributions to the acousticoutput from the headphone. Hereby the user can obtain the combination ofthese contributions that he or she judges to be the best according tothe acoustic environment in which the headphone is being used as well asto the user's specific preferences. It is of course understood thatother control means, such as the rotatable knob 1 in FIG. 1 , could beused as an alternative to the slide bar 11.

References 5 (FIG. 1 ), 6 (FIGS. 1 ) and 7 (FIG. 1 ) indicate that thegain values shown in the respective of these columns corresponds to thecurves 5, 6 and 7 respectively in FIG. 1 .

The invention claimed is:
 1. A headphone system comprising: active noisecancelling means (ANC) having a feedback (FB) signal path, a feedforward (FF) signal path, and a sidetone signal path; and a controlmember that can be displaced or rotated between opposite positions,wherein the control member is configured to control a gain of the FFsignal path and a gain of the sidetone signal path, wherein, when thecontrol member is at a first extreme position, the gain of the FF signalpath is at a maximum level and the gain of the sidetone signal path isat a minimum level, wherein, when the control member is at a second,opposite extreme position, the gain of the FF signal path is at aminimum level and the gain of the sidetone signal path is at a maximumlevel, wherein, when the control member is rotated or displaced from amiddle position in a first direction, the gain of the sidetone signalpath increases gradually from said minimum level to said maximum leveland the gain of the FF signal path remains at said minimum level, andwherein, when the control member is rotated or displaced from the middleposition in a second direction opposite the first direction, the gain ofthe FF signal path increases gradually from said minimum level to saidmaximum level and the gain of the sidetone signal path remains at saidminimum level.
 2. The headphone system according to claim 1, wherein thegain of the feedback signal path is fixed at a predetermined value. 3.The headphone system according to claim 1, wherein the gain of thefeedback signal path is variable.
 4. The headphone system according toclaim 1, wherein the control member is a rotary knob.
 5. The headphonesystem according to claim 1, wherein the control member is a slidercontrol.
 6. The headphone system according to claim 1, wherein thecontrol member includes a touch panel or one or more buttons.
 7. Theheadphone system according to claim 1, wherein the control memberincludes one single button or one single touch area configured to enablethe user to cycle through a table containing an on/off state orintermediate settings of the sidetone signal path and the FF signal pathto move one state or setting each time the single button or the singletouch area is pressed or touched.
 8. The headphone system according toclaim 1, wherein the control member includes two buttons or touch areasconfigured to enable the user to cycle through a table containing anon/off state or intermediate settings of the sidetone signal path andthe FF signal path to move one state or setting up each time one of thetwo buttons or touch areas is pressed or touched and moving one state orsetting down each time the other of the two buttons or touch areas ispressed or touched.
 9. The headphone system according to claim 1,wherein the control member is located on the headphone.
 10. Theheadphone system according claim 1, wherein the control member islocated on a device that is in communication with the headphone.
 11. Theheadphone system according to claim 1, wherein a gain of the FB signalpath defines said maximum level of the gain of the FF signal path andsaid maximum level of the gain of the sidetone signal path.